Acute pulmonary embolism: effect of a computer-assisted detection prototype on diagnosis--an observer study.

PURPOSE: To assess the effect of a computer-assisted detection (CAD) prototype on observer performance for detection of acute pulmonary embolism (PE) with computed tomographic (CT) pulmonary angiography. MATERIALS AND METHODS: In this institutional review board-approved retrospective study, six observers with varying experience evaluated 158 PE-negative and 51 PE-positive CT pulmonary angiographic studies (mean age, 57 years; 111 women, 98 men) obtained consecutively during nights and weekends. Observers were asked to determine the presence of PE and to rank their diagnostic confidence without CAD and subsequently with CAD within a single reading session. Reading time was separately measured for both readings. Reader data were compared with an independent standard established by two readers, with a third in case of discordant results. Statistical evaluation was performed on a per-patient basis by using logistic regression for repeated measurements and Pearson correlation. RESULTS: With CAD, there was a significant increase in readers' sensitivity (P = .014) without loss of specificity (P = .853) on a per-patient basis. CAD assisted the readers in correcting an initial false-negative diagnosis in 15 cases, with the most proximal embolus at the segmental level in four cases and at the subsegmental level in 11 cases. In eight cases, readers accepted false-positive CAD candidate lesions on scans negative for PE, and in one case, a reader dismissed a true-positive finding. Reading time was extended by a mean of 22 seconds with the use of CAD. CONCLUSION: At the expense of increased reading time, CAD has the potential to increase reader sensitivity for detecting segmental and subsegmental PE without significant loss of specificity.

Gallbladder and the risk of polyps and carcinoma in metachromatic leukodystrophy.

OBJECTIVES: To assess frequency of gallbladder polyposis and carcinoma in metachromatic leukodystrophy (MLD). METHODS: We evaluated 34 patients with MLD (average age 16.7 years, age range 2-39 years) screened for gallbladder abnormalities by ultrasound. In the case of cholecystectomy, findings at pathology were reviewed. RESULTS: Only 8 of 34 patients (23%) had a normal gallbladder at ultrasound. Gallbladder polyps were visible in 8 patients (23%). Cholecystectomy was performed in 11 patients (32%). In these, pathology revealed various abnormalities, including hyperplastic polyps, intestinal metaplasia, prominent Rokitansky-Aschoff sinuses, and sulfatide storage. CONCLUSIONS: Our results demonstrate that gallbladder involvement is the rule rather than the exception in MLD. The high prevalence of hyperplastic polyps, a known precancerous condition, and one death from gallbladder carcinoma at a young age suggest that MLD predisposes to neoplastic gallbladder abnormalities. As novel therapies for this patient group are emerging leading to increased life expectancy, we recommend screening for gallbladder abnormalities by ultrasound in order to prevent early death.

Childhood osteomyelitis: imaging characteristics.

BACKGROUND: The purpose of this review is to illustrate the imaging findings of childhood osteomyelitis. The diagnosis of childhood osteomyelitis can be challenging. Clinical presentation and laboratory results can differ and are relatively unreliable. To date, its role in the assessment of treatment efficacy is not yet clear. METHODS: This review article provides an overview of the different imaging modalities and imaging characteristics of childhood osteomyelitis. Levels of evidence for different modalities are presented. RESULTS: Paediatric radiology plays a pivotal role in the diagnosis of childhood osteomyelitis and can also be used to guide therapy and intervention. CONCLUSION: Although imaging is essential in the diagnostic process, cooperation between the physician and radiologist remains the cornerstone in accurately diagnosing childhood osteomyelitis. MAIN MESSAGES: • Imaging plays a pivotal role in the diagnosis of childhood osteomyelitis. • Cooperation between the clinician and radiologist is a very important aspect of making the diagnosis. • The initial imaging modality in childhood osteomyelitis is conventional imaging. • Normal conventional imaging does not exclude osteomyelitis.